M. L. Wolfrom

THIN-LAYER CHROMATOGRAPHY ON MICROCRYSTALLINE CELLULOSE.

Abstract “Avirin”, or “Avicel”, a microcyrstalline form of cellulose, has been with success in this laboratory for thin-layer chromatography. The material is employed without a binder and has, in this laboratory, essentially completely displaced the papergram because its speed, quality of separation, and the ease with which preparative plates may be run. In all cases tried it has been found that the papergram solvent systems and spray reagents are directly transferable to the new system, a finding which opens up the vast papergram literature to this type of thin-layer chromatography. By all comparisons, where both systems can be used, the method has proved superior, for technical and economic reasons, to that employing silica gel.

The Chemistry of Streptomycin

Publisher Summary The antibiotic streptomycin has been established as a meso(3,5- or 2,4-diguanidinotrihydroxycyclohexyl) α-glycoside of a disaccharide, 2- (N-methyI-α-L-glucopyranosaminido) -3-C-formyl-5-desoxy-L-aldo pentofuranose. There remains to be established the configuration of the diguanidino-inositol portion and the complete configuration of the central moiety. The diguanidino-inositol portion is designated streptidine and the central moiety is designated both streptose and streptonose. Results are cumulative and never obtained abruptly. The actinomycetes are nonmotile organisms that may be considered as intermediate forms between bacteria and molds. They occur abundantly in soils, composts, river and lake bottoms, in dust particles, and upon plant surfaces. Streptomycin proved strongly bacteriostatic against gram-positive and gram-negative organisms and thus showed promise for the treatment of many infections that are resistant to penicillin. The investigations that led to the elucidation of the chemical structure of streptomycin form a noteworthy display of the more modern methods for structural determination and comprise a valuable contribution to carbohydrate chemistry.

A new method of acetonation. Synthesis of 4,6-O-isopropylidene-D-glucopyranose

Abstract Ethyl isopropenyl ether reacts with D -glucose in N,N-dimethylformamide containing a trace of p-toluenesulfonic acid to give crystalline 4,6-O-isopropylidene-α,β- D -glucopyranose (2) in near-quantitative yield. The structure of 2 was established by n.m.r. spectroscopy of it and of its β-triacetate 3, and by conversion of 3 through deacetonation and subsequent acetylation into β- D -glucopyranose pentaacetate (5). The acetonation reagent operates under kinetic control, with favored attack at primary hydroxyl groups, instead of by the thermodynamic control associated with conventional acetonation methods. The reagents converts methyl α- D -glucopyranoside (7) into the 4,6-isopropylidene acetal 8, and D -mannitol (9) into a 2:1 mixture of the 1,2:5,6-di-isopropylidene acetal 10 and the 1,2:3,4:5,6-tri-isopropylidene acetal 11.

Trifluoroacetyl as an N-protective group in the synthesis of purine nucleosides of 2-amino-2-deoxy saccharides

Selective N-(trifluoroacetyl)ation of 2-amino-2-deoxy-D-glucose, followed by O-acetylation, gave the anomeric 1,3,4,6-tetra-O-acetyl-2-deoxy-2-(trifluoroacetamido)-α(and β)-D-glucopyranoses (3 and 4). Conversion of 3 and 4 into the bromide, followed by condensation with 6-benzamido-9-(chloromercuri)-9H-purine, produced 6-benzamido-9-[3,4,6-tr-O-acetyl-2-deoxy-2-(trifluoroacetamido)-α-D-glucopyranosyl]-9H-purine and the corresponding β-D anomer. Removal of substituent groups was achieved by means of methanolic ammonia, giving the anomeric, crystalline 9-(2-amino-2-deoxy-α(and β)-d-glucopyranosyl)adenines. Application of this procedure to 2-amino-2-deoxy-D-galactose gave, as the final products, 9-(2-amino-2-deoxy-α-d-galactopyranosyl)adenine and the corresponding β-D anomer, characterized as their crystalline dihydrochlorides.

On the distribution of sulfate in heparin

Abstract The crystalline barium acid salt of heparin (after conversion into the sodium salt) was oxidized with periodate, whereby its d -glucuronic acid residues were destroyed. The oxidized material was reduced with borohydride; the product was treated with acid, and then deaminated with nitrous acid. From the deamination mixture, 2,5-anhydro- aldehydo - d -mannose 6-sulfate was isolated as its crystalline brucinium salt, and identified by comparison with authentic material. This work definitively places the two sulfate groups (per tetrasaccharide unit) on C-6 of the 2-amino-2-deoxy- d -glucose residues, and shows that the d -glucuronic acid residues are not sulfated.

The isolation of l-iduronic acid from the crystalline barium acid salt of heparin

Abstract The thrice-recrystallized barium acid salt of heparin was hydrolyzed by a modified Monier-Williams method with 72% sulfuric acid at 25°, followed by dilution and refluxing. The uronic acid fraction (13%) of the hydrolyzate was chromatographically shown to contain d -glucuronic acid, l -iduronic acid, and their lactones. The l -iduronolactone component was isolated, and characterized as the crystalline brucinium salt of its acid. It was established that the l -iduronic acid was derived neither from contaminant dermatan sulfate nor through C-5 epimerization of d -glucuronic acid. Previous hydrolytic conditions (which gave, in addition to 2-amino-2-deoxy- d -glucose, only d -glucuronic acid or d -glucose from purified heparin or its partially carboxyl-reduced derivatives, respectively) are now considered to have been too drastic to give all of the representative, degradation fragments.

Hydrolytic sensitivity of the sulfoamino group in heparin and in model compounds

Abstract The hydrolytic constants of the sulfoamino group in crystalline methyl 2-deoxy-2-sulfoamino-α- d -glucopyranoside and in amorphous preparations of methyl 3,4,6-tri-O-methyl-2-deoxy-2-sulfoamino-α- d -glucopyranoside, 2-deoxy-2-sulfoamino- d -glucose, and heparin in 0.1 N hydrochloric acid at 99.5 °C. are, respectively, 0.0565, 0.056, 0.068, and 0.062 min.−1. The rates of sulfate release in 0.1 N hydrochloric acid, at 99.5 °C., of heparin, chondroitin sulfate, and methyl 2-deoxy-2-sulfoamino-α- d -glucopyranoside are compared as well as are the rates at which heparin and methyl 2-deoxy-2-sulfoamino-α- d -glucopyranoside are deaminated with nitrous acid at 27 °. The results are self-consistent and show that it is highly probable that all the nitrogen in heparin is present as a sulfoamino group in the hexosamine portion, with the exception of some 6% of the total nitrogen which was unsubstituted in the preparation studied. A procedure suitable for the estimation of sulfate ion in the presence of labile bound sulfate and of sulfomucopolysaccharide is described.

Osage orange pigments—XVII.: 1,3,6,7-tetrahydroxyxanthone from the heartwood

Abstract 1,3,6,7-Tetrahydroxyxanthone has been isolated from the heartwood of the osage orange ( Maclura pomifera Raf.). The occurrence in this wood of morin and of 2,3′,4,5′-tetrahydroxystilbene has been confirmed. Certain biogenetic relationships among the eight known pigments of this tree are discussed.

Amination of amylose at the C-2 position1

Abstract 6- O -Tritylamylose was oxidized with methyl sulfoxide and acetic anhydride, and the product oximated; the oxime was reduced and detritylated, and the product dialyzed. The resultant, colorless solid contained, on C-2, an amino group (D.S. 0.8) which was almost entirely oriented as in the d - gluco configuration.

The Effect of Ionizing Radiations on Carbohydrates

Selected carbohydrates underwent color and organoleptic changes on irradiation in the solid state. On irradiation in aqueous solution, a selective oxidation of the terminal primary hydroxyl groups of D-glucitol (sorbitol) and D- mannitol occurred, with the formation of glucose and gulose from the former and of D-mannose (isolated as beta -D-mannopyranose pentaacetate) from the latter. Arabinose and xylose (from D-glucitol) and arabinose alone (from D-mannitol) were also formed, and at high doses D-mannitol yielded mannuronic acid. These changes were established by paper chromatographic methods. D-Glucose and D-fructose (especially) undergo radiation damage in aqueous solution. Irradiation of the disaccharides sucrose, maltose, and cellobiose, and the trisaccharide raffinose, demonstrated that the glycosidic bond is especially sensitive to the action of ionizing radiations and that the order of hydrolysis is qualitatively that found with acid hydrolysis. Hydrolysis of the disaccharides and trisaccharides increased with increasing irradiation dosage. (auth)